What is the greatest common factor of $9$ and $5$ ? Another way to say this is: $\operatorname{gcf}(9, 5) = {?}$
Answer: The greatest common factor is the largest number that is a factor of both $9$ and $5$ The factors of $9$ are $1$ $3$ , and $9$ The factors of $5$ are $1$ and $5$ Thus, the greatest common factor of $9$ and $5$ is $1$. $\operatorname{gcf}(9, 5) = 1$